LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2008 >> LS 600hL >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Air Conditioning >> Air Conditioning System >> DTC B1462/62 Room Humidity Sensor Circuit >> Inspection Procedure

Inspection Procedure

  1. READ VALUE USING INTELLIGENT TESTER OR TECHSTREAM (HUMIDITY SENS) 
    1. Use the Data List to check if the room humidity sensor is functioning properly
      1. Intelligent tester

        AIR CONDITIONER 

        DATA LIST

        Tester Display Measurement Item / Range Normal Condition Diagnostic Note
        HUMIDITY SENS Humidity Sensor /
        Min 0%, Max 100%        		 Actual room humidity is displayed -
      2. Techstream

        Air Conditioner 

        DATA LIST

        Tester Display Measurement Item / Range Normal Condition Diagnostic Note
        Humidity Sensor Humidity Sensor /
        Min 0%, Max 100%        		 Actual room humidity is displayed -

        OK: The display is as specified in the normal condition. 

    NG: Go to step 2 

    OK: REPLACE AIR CONDITIONING AMPLIFIER  (See REMOVAL  )

  2. CHECK WIRE HARNESS (ROOM TEMPERATURE SENSOR - A/C AMPLIFIER) 
    1. Disconnect the L37 room humidity sensor (room temperature sensor) connector.
    2. Disconnect the L77 air conditioning amplifier connector
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTOR SPECIFIED CONDITION CHART

      Tester Connection Condition Specified Condition
      L37-3 (RH) - L77-31 (RH) Always Below 1 Ω
      L37-4 (S5) - L77-5 (S5-1)
      L37-2 (-) - L77-32 (SG-1)
      L77-32 (SG-1) - Body ground Always 10 kΩ or higher
      L77-31 (RH) - Body ground
      L77-5 (S5-1) - Body ground
      Fig 1: Identifying Terminals Of L77 Air Conditioning Amplifier And L37 Room Humidity Sensor Connectors
      G05774310Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  3. CHECK AIR CONDITIONING AMPLIFIER (S5-1 - SG-1 VOLTAGE) 
    1. Remove the air conditioning amplifier with its connectors still connected.
    2. Measure the voltage according to the value(s) in the table below

      Standard voltage 

      TESTER CONNECTOR SPECIFIED CONDITION CHART

      Tester Connection Condition Specified Condition
      L77-5 (S5-1) - L77-32 (SG-1) Power switch ON (IG) 4.5 to 5 5 V
      Power switch OFF Below 1 V
      Fig 2: Identifying Terminals Of L77 Air Conditioning Amplifier Connector
      G05774311Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE AIR CONDITIONING AMPLIFIER  (See REMOVAL  )

    OK: Go to next step 

  4. INSPECT ROOM TEMPERATURE SENSOR (ROOM HUMIDITY SENSOR) 
    1. Remove the room humidity sensor (room temperature sensor).
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTOR SPECIFIED CONDITION CHART

      Tester Connection Humidity Condition Specified Condition
      2 (-) - 3 (RH) 10% 0.70 to 1.08 V
      20% 0.72 to 1.57 V
      30% 1.13 to 1.95 V
      40% 1.61 to 2.24 V
      50% 1.99 to 2.46 V
      60% 2.26 to 2.66 V
      70% 2.48 to 2.85 V
      80% 2.68 to 3.04 V
      90% 2.87 to 3.05 V
      NOTE:
      • Do not touch the humidity sensor as body heat will affect the inspection results. When performing the inspection, hold the sensor by its connector.
      • Allow the sensor to acclimate to the ambient temperature and humidity before performing the inspection.
      • The standard voltages in the table above are based on inspections performed when the ambient temperature is 25°C (77°F).
        Fig 3: Humidity Versus Voltage Graph - Room Temperature Sensor (Room Humidity Sensor)
        G05306854Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE ROOM TEMPERATURE SENSOR  (See REMOVAL  )

    OK: REPLACE AIR CONDITIONING AMPLIFIER  (See REMOVAL  )

scientia non olet · About LEMON Manuals